Respiratory function and respiratory muscle strength in adolescent idiopathic scoliosis

It was aimed to analyze the relationship of the respiratory functions, respiratory muscle strength, magnitude of the curvature, angle of trunk rotation (ATR) and brace-wearing duration in patients with adolescent idiopathic scoliosis (AIS).

Sixty patients with AIS (43 females), with maximum Cobb angles between 20° and 66° were included in the study. ATR values were measured with a scoliometer. Respiratory function parameters (forced vital capacity [FVC], forced expiratory volume in one second [FEV1], FEV1/FVC ratio, peak expiratory flow [PEF]) and respiratory muscle strengths (maximum inspiratory pressure [MIP] and maximum expiratory pressure [MEP]) were measured by combined spirometry.

There was a negative significant correlation between maximum Cobb angle and ATR with respiratory function parameters except for PEF and FEV1/FVC (r = -0.258-0.441; p = <0.001-0.047). There was a moderate negative correlation between ATR with MIP (cmH2O) (r = -0.377; p = 0.003) and MEP (cmH2O) (r = -0.362; p = 0.005). On the other hand, no correlation was found between brace-wearing duration with respiratory functions, maximum Cobb angle and brace-wearing duration with respiratory muscle results.

The results of this study showed that, respiratory functions were normal or mildly affected, and respiratory muscle strengths were weak in AIS. Increased Cobb angle and ATR negatively affected respiratory function; increased ATR was associated with decreased inspiratory and expiratory muscle strength. It is extremely important to carefully evaluate the respiratory system and to know the variables that affect respiratory functions and respiratory muscle strength in achieving optimum recovery in the holistic treatment of individuals with scoliosis.